Sunday, May 3, 2015

Modelling the Turin Shroud: my flour/nitric acid vapour model looks better and better with each passing day.

Here's a quickie progress report, so for now I'll simply post pictures with captions only. Profoundly deep and penetrating physicochemical insights and analysis, guaranteed (says he) to knock your socks off, can wait till later.

The previous posting reported the use of a cooked paste of white flour and water in the initial imprinting of my own hand. But  there are theoretical advantages in using a dispersion of raw, uncooked flour (intact endosperm cells, enclosing native starch granules,  bla bla, less risk of reverse side penetration and image, bla bla).

Fig. 1: OK, so here's that hand again, but this time it's been painted with a thin slurry of uncooked white flour and water. (I might experiment with additives later to get a more even coating, but if the procedure works without them, albeit sub-optimally, then it makes for a more credible model.

Fig.2: If I had to choose just one picture to illustrate the power of the new technique (at Stage 1 imprinting) this would be it. Look how well the linen moulds to the hand. It's almost as if it had been painted white, instead of being covered with fabric. Why?

Fig 3: Here's the same in a separate experiment. Amazing, yes? Even the surface veins, sinews and fingernails show up.

Fig 4: This picture too is amazing in its own way, except that the reason is not self -evident unless you do the experiment for yourself. When one goes to lift off the linen, one finds it is STUCK onto the hand, and that considerable force is needed to peel it off, and that one's hand at the end is almost bone dry, with flecks of dry flour here and there. In other words, flour slurry behaves like superglue when it meets linen. (I predicted that in the previous posting, but let's not bother with the reasons why, except to say that like attracts like in organic chemistry, which accounts for the phenomenon of surface ADHESION, a neglected factor that needs to be considered in imprinting by physical contact).

Fig 5: So much effort is needed to peel back the linen (at least with raw flour) that the fibres of the linen become pulled away from their threads to form a sort of fluffy fleece. One can just about make out adhering particles of flour in the picture above. Might the boosted  'fleece' have something to do with the subtlety of the TS image, its indistinct boundary between image and non-image areas?  Or the ease of detaching image fibres vis-a- vis non-image (see STURP's Raynond N.Rogers)? Maybe, maybe not, but the results so far underline the importance of doing open-ended experimentation that just once in a while can throw up effects that are largely unpredicted, yet may or conceivably might play a key role in understanding the 'iconic' or 'enigmatic' TS image.

Fig.6: We've now moved from Stage 1 (imprinting) to stage 2 (image development). The imprint of my hand has been folded into a compact bundle (with securing stitches of cotton thread) and suspended over a tank containing conc (70%) nitric acid. It's the vapour that develops the image (see previous posting). Yes, nitric acid was known in the 13th/14th century (see my earlier posting on the writings of Pseudo-Geber, probably one and the same as the Franciscan monk/alchemist Paul of Taranto)

Fig.7: Well, that was a most welcome result, showing that the raw wheat flour worked as well, if not better than the cooked flour, despite having an entirely different consistency (the raw dispersion was thin and milky, nothing like to the thick gooey paste from boiled flour).  Predictably, there was less reverse side penetration and imaging.

Fig.7: Here's the linen being steeped in sodium bicarbonate solution to neutralize the surplus of nitric acid vapour adhering to the linen. (On this occasion, the linen had not been noticeably weakened by overnight exposure to nitric acid vapour, as checkied later).

Fig.8: Although not obviously weakened, the linen had acquired a faint beige coloration ("aged look"?). That can be seen in this photograph, where it has been placed on top of the same untreated linen.

Fig.9: Yes, there is a faint reverse side image (unwelcome for modelling purposes, though whether it would be so obvious against a centuries-old ageing is a moot point). But beware artefacts: one is seeing it here  against the same white background. See my previous posting for the false impression that can be created by back-reflection of filtered/coloured light from white of light-coloured backgrounds. Reverse-side images should always be checked against matt black backgrounds that prevent back-reflection through the interstices of the weave.

Fig 10: Here's the topside image, viewed against a black background, after neutralizing acid, rinsing, drying, and ironing.

Fig 11: Here's the reverse side, against the same black background. There is scarcely any reverse side image. Might the traces be removable, e.g. with soap and water, while still leaving front side image?

Fig.12: I had earlier wondered whether the nitric acid step in the new procedure could be replaced by plain-old oven incubation.  The answer would appear to be no. Oven temperatures in the region of 200 degrees Celsius that turn the flour imprint into a yellow/brown image also have an excessive darkening effect on the linen itself.  (The test was done with a metal template loaded with flour slurry at decreasing solid/water ratio: imprints were nothing like the TS image, being scab-like, and vigorous brushing failed to 'soften' the images).

Fig 13: At this stage I decided to do some before-and-after tests on the hand image. Thus the vertical cut to divide it into two approximate halves.

Fig 14: it's maybe not easy to spot, but a length of sticky tape between labels A and B has been pressed onto the image/non-image areas, which was then stripped off and stuck onto a glass slide  for later microscopy. The triangular notches were to remind where the sticky tape had been applied.

Fig.15: That's the slide with sticky tape. Shame about the air bubbles, but one can see stripped-off linen fibres peeping out from the tape at the top. They don't look highly coloured (but then this a more subtle model system than contact scorching).

Fig. 16: We're now about to see how much of that flour/nitric acid image can be washed out with soap AND vigorous rubbing. Is the image simply adhering flour (nitric acid-modified) or are there grounds for thinking that the technique has also chemically modified and coloured the linen fibres per se?

Fig 17: Here we are an hour or so later. The quality of the photo is not that good, with the (artefactual?) vertical,banding that might have been a trick of the light. Nevertheless, if one looks closely one sees that the image has NOT been completely washed out with soap and vigorous rubbing. There is a faint yellow DIFFUSE image area, ie. my fingers, suggesting that the technique has resulted in coloration of linen fibres, despite using an external agent (white flour) to kick start the process of coloration.

Fig 18: Finally, when one turns the linen over, against the black background, there's scarcely any reverse side imaging.maybe not suprising given the particulate nature of the imprinting medium (whole endosperm cells of wheat flour that don't readily penetrate the weave, even from a thin dispersion).

However, the key finding of this exercise must surely be the way that the linen moulded itself to the contours of my hand, despite using a thin milky flour dispersion, so as to show up an amazing degree of detail. that has surely to be a big plus in any model that relies on contact-imprinting. That same capture of detail is then apparent in the final developed imprint. We seem to have a highly promising model here that challenges the pro-authenticity view that the TS image is too subtle to have been produced by conventional physics and chemistry. Never write off conventional physics and chemistry. The ability of molecules to interact and self-organize should NEVER be under-estimated. It's almost as if they have minds of their own (in a sense they do, given their quantized energy levels that became permanently imprinted at an early stage in the history oif the Universe (stellar nucleosynthesis).

Update:Monday May 4

I flagged up this posting yesterday on Dan Porter's  shroudstory site, currently celebrating its 3,000,000 views, with this comment:

May 3, 2015 at 5:24 pm
Hello again folks. Have today found that the results with the new model can be obtained using a thin slurry of white flour with COLD water with a consistency intermediate between that of milk and single cream. Have today posted 18 new photos.
While I had predicted earlier on theoretical grounds that native wheat endosperm cells, such as exist in uncooked white flour, would bond well to linen fibres (due to like-for-like attraction of primary cell walls of similar chemical composition) I never for a moment imagined just how well. Not only does the flour dispersion behave like an instant adhesive, bonding the linen to skin, but it also makes the linen conform closely to body relief:

Isn’t that amazing?
It then took a bit of effort tearing the linen away from my hand for Stage 2 development (nitric acid vapour, as before). Superficial linen fibres were broken in the process, creating a kind of fleece. Might a similar bonding at the imprinting stage have contributed to the ‘iconic’ nature of the TS image (i.e.fuzzy, ghostly quality) one wonders?
I’m thinking of doing a facial selfie using the new technology, but may have to cut the imprint into quarters for separate development, given the limited capacity of my developing tank (the size and shape of a goldfish bowl).

Here's the response from my friend DavidG (who seems uncharacteristically to be having an off day) and my reply:

  • May 3, 2015 at 8:04 pm
    Paper mache? I too am amazed at the result of your experiment but we aren’t looking for a 3 dimensional image model, just one that photographs that way. Or is this merely a stage which leads to that model later?
May 3, 2015 at 11:20 pm
Oh dear. Methinks you need to visit my site, DavidG, and remind yourself of how the new (old?) technology works. ;-)
In brief: paint a portion of one’s own or someone else’s anatomy with a milky-white suspension of white wheat flour in water. Press the painted part of that anatomy into linen to leave a very faint, indeed near-invisible imprint. Leave the imprint to dry, then suspend the linen above conc. nitric acid taking all the necessary precautions (gloves, eye protection, face mask, ventilation, lab technician training etc etc). The HNO3 vapour reacts chemically with flour constituents (proteins, carbohydrates etc) to ‘develop’ the latent image. Not for nothing do I call it “chemography” which, like pre-digital photography, is a two-step procedure: capture of latent image, followed by chemical development.
I say that 13th/14th century alchemists (especially) had the technology, given that flour was a dietary staple, and Pseudo-Geber/?Paul of Taranto had described the preparation of nitric acid vapour by heating a mixture of saltpetre (potassium nitrate), Cyprus vitriol (copper sulphate) and alum (potassium aluminium sulphate). The imprinted linen could have been suspended in the hot vapour to get rapid yellowing and image development. Alternatively, the vapour could have been condensed in a cooled collecting vessel to get conc. nitric acid, and the linen suspended in the cold vapour above the liquid to get slow colour development as in my procedure, which takes several hours.

Update: Monday May 4

Decided to do a selfie this morning, using the new technology.

Surprisingly, it needs only a thin smear of flour slurry on one's face to get a decent imprint.

Yes, I used a mirror to get this pre-breakfast picture of the slurrified me, immediately before pressing my face down into linen, underneath which was a cushion and several layers of bath towel. Yup, I used LUWU geometry for starters (more predictable, the degree of contact being determined mainly by the deformability of the underlay, there being no manual moulding as in LOTTO. (LUWU = Linen Underneath, Then Underlay; LOTTO= Linen On Top, Then Overlay).

Here's the resultant imprint, before development. shown 'as is' (no photoediting).

Here's the same, after some minor adjustments to contrast and brightness. Note the apparent moustache, and beard and bushy eyebrows. Hmmmm. 

The linen has been folded twice to make a more compact package, using a few stitches of red cotton and is now ready to be suspended in nitric acid vapour.

 Here's the linen inside the vapour chamber. Once can just make out a red stitch. Unfortunately one corner dipped briefly into the nitric acid solution , but that was spotted before there was too much capillary uptake.

All we have to do now is wait. Started vapour treatment at 7:10 am. It's now 13:45, and there's an easily visible browning. I shall leave it for another hour or two before removing, airing, neutralizing  excess acid in bicarb solution, rinsing, drying and ironing.  We shall see what we shall see.

Update  16:10 May 4

OK. Here's the result of my first facial imprinting, using LUWU geometry:

That's the 'as-is' imprint. Anyone would think I had a beard and moustache.
 See my posting from 10 months ago:

 (See there for what happens to the little girl's face when pressed up against glass, such that the photograph taken from the other side becomes an 'impactogram')

Pity about the nose - it may have looked better if the linen had not dipped briefly into the acid solution.

That's a Secondo Pia style inversion of tones (positive to pseudo-negative) using ImageJ Edit Invert.

That's the image after applying some 3D enhancement in ImageJ.

That's the same as above, applying autocorrect in my photoediting program.

Conclusions: the technique shows promise, but falls well short of the TS image characteristics. Next step: I shall have to switch from LUWU to LOTTO. It's almost certainly the passive imprinting technique, relying solely on deformation of the underlay to give moulding of cloth to linen that is responsible for the rather inferior result. LOTTO involves manual moulding, which ensures that important relief is not missed, while at the same time risking excessive capture of sides, resulting in lateral distortion. But then Luigi Garlaschelli believed that a bas relief had to be used for the face. Maybe he's right.

Late addition: I realize from holding the imprint up to the light that there has been failure to develop the brow ridges:

I say failure of development, because they were clearly imprinted with flour, as one can see above. Those missing brows make the image look incomplete.

The linen will now go back in the vapour chamber in an attempt to produce complete development. It may have been the way the cloth was folded that resulted in only partial development.

Result: comparing one with two nitric acid exposures:

How strange. One of the missing "eyebrows" (more correctly brow ridges) has now imaged (viewer's right), but not the left (which shows white due to uncoloured flour).  The reasons for the failure to image first time (both brows) and the second (one brow) are many, due to technical as well as scientific reasons. The whole face imprint is really too big for my vapour chamber if the truth be told.  If only I had one of those tall,  thick-walled glass chromatography tanks. One needs to be more modest with plans right now,  switching to a smaller, less ambitious, less demanding template.

New addition: 17:00 May 5

I was asked by piero on shroudstory a day or two ago whether I'd considered the targets for nitric acid in flour and linen. Lignin was one he mentioned. I'll try and track down the thread in question. Suffice it to say that there's a handy model system I mentioned for checking out lignin. It's pear flesh, the slightly granular feel of which in the mouth is due to clumps of lignified cells ("stone cells"). If nitric acid goes for lignin, those stone cells should show up.

Well, they do:

Pear flesh was crushed onto a strip of linen, and after drying the strip was cut vertically into two sections. The left half was the control (no nitric acid vapour) and the right half was the test. Prediction confirmed: the stone cells show up clearly after nitric acid. Lignin, of which there's substantial amounts in linen,  is indeed a target.  Follow-up studies will be done using the microscope, but not immediately.

Here's the thread in question:

April 29, 2015 at 9:33 am
Where are the controls on linen fibrils (= inspections under a microscope)?
We have not yet seen the controls at “sub-fibre level” …
You know that Shroud image reproduction fails if the features of linen fibril is not the same of the linen fibrils of the Shroud…
Until we have not seen what are the true features (remember also the question of colorless medulla) we cannot speak about the interesting experiments you have done.
— — —
B.T.W. I have read that :
>cold nitric acid, i. e. at ordinary room temperature, either alone
or in combination with certain other acids, will not deleteriously attack
the fiber of flax straw or tow but will attack and reduce the woody portion or shives,
which, as is well known, comprise cellulose fibers associated
with encrusting or adsorbed lignin.
Have you studied the nitric acid action (reaction) on lignin ?
— —
Perhaps we can also try to detect where are (= maps)
the reacted lignin constituents (during the controls on linen fibrils)…
— —
I’m too impatient, I’m sorry…
— —
In any case I believe that new AFM controls on linen fibrils
are based on something more substantial
than the Mark Evans photomicrographs.

  • April 29, 2015 at 9:58 am
    Piero:I shall be doing all the tests you suggest and more besides, but all in good time. For now I have been content to flag up the results of my pilot experiments with the new two stage imprinting/developing methodology. They show how it’s possible to get a yellow-brown negative imprint from a real person that shows some 3D-properties.There’s a little reverse side colour, but less than I expected, and simple modifications may be able to prevent it altogether. Image superficiality has still to be determined, but then chemical degradation does not always show itself as visible discoloration: there may be less superficial damage to the SCW core of the fibre, the hemicelluloses especially, that are not easily visible, maybe not visibly affecting the ‘medulla’, i.e. most central part, thus distinguishing the new technique from the alleged defect of the contact-scorch model.
    Being aromatic, lignin is a possible target for nitration as well as oxidation. I’m thinking of using the stone cells of pear fruit as a model system for looking at linen lignin, given the ease of seeing them under the microscope. However, it’s not impossible that the result obtained with nitric acid could be reproduced using acid-free thermal development alone, given the right imprinting agent, perhaps not the wheat flour paste used in my preliminary experiments. There’s a vast number of variables and combinations thereof that need to be tested. It will take time.

    Update: Tuesday May 5,  07:00

    Yes, the face is difficult, at least a fully 3D face, as on a real person or 3D effigy thereof, whether bust/statue/dummy etc As mentioned earlier, Luigi Garlaschelli abandoned attempts to imprint off a real face with his powder frottage model, opining that in a medieval provenance, a bas relief would have been used for the face. Certainly that TS face has a mask-like character, noting especially the abrupt cut-off between cheek and hair (which some explain away as a banding-effect in the linen, a view this blogger has refused to buy into for various reasons).

    So where do we go from here?

    First, I'm not entirely certain that 100% flour is the optimum imprinting medium (while attractive in pilot experiments for its simplicity). Already there's a hint that an excess of flour tends to cake-on at pressure points, notably the brow ridge, and then for some reason that I cannot explain, resists colour development with nitric acid (I suspect it's something to do with the balance between water vapour and nitric acid vapour: if water vapour cannot readily penetrate the hard cake, then the nitric acid cannot do its job). So today I am going to compare three mixes, using a smaller 3D template than a face or hand. The mixes?  100% flour/water; 100% beaten egg yolk ("egg tempera" as used by medieval artists before the arrival of Renaissance oil piants), and a 50/50 mix of each.

    3D template, choosing a new site with  mainly flat (tish) surfaces with interesting detail? I've decided to use my toes. I'll paint the underside with the mix, then the topside, then step onto linen to get a LUWU imprint, then turn the surplus of linen up and over the end of the toes, and mould gently to the top surface to get a LOTTO imprint. It's a model version of the TS itself, note, but using the opposite extremity of the body for the up-and-over reversal of cloth direction. It will also make a more compact package than a face or hand in my vapour chamber!

    Update: Tuesday May 5, 19:00

    Here's an image I shall shortly post to shroudstory.

    It's one of some 200 pages in a 9th century gospel that is still in almost perfect condition. The idea that age always degrades inks and pigments is clearly mistaken. An image that is not due to ink or pigment, but a chemical modification of the matrix itself, is likely to be even more permanent.


Tuesday, April 21, 2015

Might this be how the Turin Shroud was faked, using medieval alchemy?

Here it is folks: the best I can offer after more than 3 years  of almost non-stop experimentation : Model 9  ("the nitric acid model").

Alternative name (afterthought, added 25th April): this new technique produces what might be called a "tactile chemograph".  Maybe there was only one ever produced (the image that we now call the Turin Shroud).  The tactile chemograph may be thought of as a forerunner of the photograph. (In both instances, one produces a latent image from a real person without harming them in any way, one that can then be developed in a bath (or vapour chamber) with the appropriate developing chemicals.

That's my own (right) hand.  Behind it is a negative image on linen of my (left) hand produced using the new (?) technology. I've had to mix left and right to make a comparison (imprinting not only produces a negative image but  left-right reversal too)

Here's the same negative image in close-up. I've cut out the unsightly part where there was excessive manual  moulding of linen to side relief (but was able to utilize the removed portion for fruitful experimentation).  As mentioned in the preceding posting,  the cut out was used to test the effect of neutralizing the excess nitric acid, with the unexpected effect of enhancing both image colour  (yellow to yellow-brown) and the contrast CHEMICALLY - not digitally.

Details will follow. That's if anyone is interested (comments invited- see sidebar for quick link).  If not I'll leave it at this - short and (arguably) sweet and take a holiday from scientific model-building for a while (weeks rather than days).  It can be an exhausting business, and somewhat hazardous too when fumes off concentrated nitric acid are my suggested means for  producing the elusive result - that 'enigmatic'  and highly superficial Shroud of Turin image - at least at the macro level.

Reminder (from posting preceding this one):

Step 1:Imprint off 3D template (possibly a real person, living or dead OR an effigy thereof in wood, stone, clay etc) painted with heat-gelatinized white flour.

Step 2. Develop the proto-image by exposing to nitric acid (HNO3) fumes

Step3. Neutralise the unreacted acid in the fibres (e.g. by dusting with chalk, or rinsing with lime water).

Here's an earlier picture showing the crucial testing of the third step (neutralization of acid) performed on the unsightly excised portion of the hand imprint.

The portion on the right is the untreated control, i.e. hand imprint after partial dissipation of nitric acid fumes in air (outdoors!).

The left hand portion was cut off between the two crosses. That.s when I noticed the stiff nature of the image area with a coarse texture (hardly surprising, given that flour is mainly starch). Would the stiffness disappear if the cloth were washed, while leaving the image? But first, there was another test that could be done before wetting the fabric. I crumpled and kneaded the fabric. Immediately the fabric in the image area began to disintegrate, assisted no doubt by the presence of the stiffening agent that assisted thread fracture. All the more reason, then, to minimise the weakening of the linen by getting the fabric from the fumigation chamber into a weak alkali solution ASAP. The left hand portion in the photo above was the appearance AFTER doing just that - immersing the offcut in sodium bicarbonate solution, testing before and after with pH indicator to check that acid had been neutralised, then rinsing thoroughly and drying.  Not only had the image not washed out, but it had intensified and changed from yellow to yellow-brown, becoming arguably more Shroud-like.

Expect some more experimental details to be added in the next day or two, plus the results of imprinting off a miniature effigy made from moulded clay (after air-drying and sealing).

That's the home-made template on the right, alongside the brass crucifix used in so many of my previous "heat scorch" experiments. Quick-drying emulsion paint was used as a sealant (what would medieval folk have used to seal the pores of unfired earthenware on wonders?). Imprints are developing in acid fumes (locked garage) as we speak.

Some details re the imprinting technology thus far (as promised)

I used my right hand to paint the left one with a thick paste made the previous day using white flour and hot water (it set to a gel overnight in the fridge, which reverted to a paste on stirring). Linen was placed on top, as shown, and then pressed down firmly to produce an imprint on the underside of the linen. Note the considerable detail in the imprint, even at this early stage.

Here's an early stage in setting up the fumigation (garage! eye protection?  face mask! ).

The linen with its flour imprint has been stuffed into the 'goldfish bowl', secured with the blue tape to leave a clearance between fabric and base to leave room for acid. The concentrated nitric acid (hazardous! not for the faint-hearted) is then introduced via the funnel so as to form a 1cm deep layer under the fabric without touching it directly. The idea is to funigate the image. After carefully removing the funnel a sheet of glass was used as a lid, weighed down to get a reasonable seal. The garage was then vacated ASAP and locked with a no-entry sign on door. Chemical development took place overnight.

Here's the imprint after development with nitric acid, but before neutralizing the excess acid. There's not a lot to see at this stage, and it's still a chemical hazard, needless to say.

Here's the developed imprint in the wash hand basin, ready for rinsing and neutralization of unreacted acid with sodium bicarbonate.

Ready to neutralize the excess acid.

The acid has been neutralized (the pH now being greater than 7). Already the image on the linen looks darker (now more brown than yellow).

Final step: after thorough rinsing and drying, the imprint can be safely ironed, ready for displaying on one's blog... 

Note: there are no reasons for thinking this image is not a permanent one, but time will tell.

All the photos on this posting are 'as is' from the camera. Apart from cropping, there have been no changes to brightness, contrast or other photoediting.

Afterthought: who'll be first to say that I've failed to produce a perfect facsimile copy of the fingers on the Shroud - that mine are ordinary everyday sort of fingers, not the spindly unnaturally elongated fingers one sees on the Shroud?  As for the hint of fingernails on my image - well, that rules it out of contention straightaway! You read it here first.

Afterthought to afterthought: there's a simple answer to those overlong fingers on the Shroud. The subject was alive, say a non-deceased medieval monk, and his hands shifted during the imprinting process. Maybe the imprinter briefly applied to much pressure, causing the hands to slide on the slippery abdomen, creating a skid-mark effect, captured for posterity.

Update:  Wednesday 22 April, 15:10

I have a new imprinting medium, a very different one from the flour gel used so far. It's of animal origin, not plant, it requires much shorter development times, and if I'm not mistaken, appears to protect the background non-image areas of linen (maybe 'trapping ' nitric acid more efficiently?). What's more it was well known in medieval times, indeed for millennia.

Here's what an imprint off my trusty brass crucifix looks like with the new wonder material after neutralizing excess acid, and applying the autocorrect menu option to the snapshot:

 Here's a light/dark reversal, using the Edit Invert function of ImageJ (autocorrected for additional contrast).

Update: Wednesday April 22, 22:00

Here's a further responses or rather query, regarding  the new model, appearing just now on, and my immediate reply.

April 22, 2015 at 3:04 pm
Can you explain in detail the advantages of your new hypothesis with regard to your ‘old’ scorch hypothesis

April 22, 2015 at 3:47 pm 
Off the top of my head (maybe with afterthoughts later):
1. One can imprint off a real person (or statue, bas relief etc). The imprinting medium (flour paste etc) is non-injurious to skin.
2. One can mould the linen to contours manually if desired, capturing as much or as little of the 3D relief as one wishes (with more or less risk of lateral distortion).
3. Development of the image in the fumigation chamber can be monitored visually at intervals over minutes or hours until one has obtained optimum image intensity, and the least damage to linen fibres.
4. Retained acid fumes after development can be neutralized, either with lime water, or by dry dusting with powdered chalk. However, some weakening of fibres must be expected.
5.The end-product can be claimed to be an ancient sweat imprint, left on Joseph of Arimathea’s linen when the body was transferred from cross to a makeshift stretcher/body bag.
6. The technique allows for blood (or blood substitute) to be applied at the same time as body-imprinting medium, provided the blood or substitute stays red in nitric acid fumes (real blood does not – it quickly turns a brown colour). Blood would have been applied after. i.e. directly on top of the gooey imprinting medium to account for there being no body image under Shroud “blood”.
7.The use of an extraneous organic material (flour etc) allows for the possibility of the newly-imprinted and developed image being conspicuous, but slowly fading over the centuries as the pigmented material flaked off or became otherwise degraded, provided there was a fairly stable “ghost image” left behind, the one we see today.
8. When applied to new linen, the technique has a side-effect that would be seen as a bonus – artificial ageing of the linen. Centuries later, pro-authenticity chemists and others would be delighted to find there was less potential vanillin and more mechanical weakness than would be expected of medieval linen a mere 700 years old.
9. An imprint developed by oxidation and/or other chemical reactions may (or may not) lack the fluorescence of a thermal scorch image.
10. Chemical action of limited duration may result in more superficial change to linen fibres than is possible by thermal scorching, such that one sees no colouring at the interface of the SCW and central lumen. Reverse-side coloration can be minimized by suitable adaption of technique (thick linen, use of sizes to block up pores, use of viscous imprinting media etc).
As properly noted, all this is simply an hypothesis at this stage, one that will need a lot of experimental work to evaluate, with the possibility of premature paradigm death at any stage. However, I shall be taking a break from experimental work for at least a fortnight probably longer, these last few weeks having been fairly hectic, spent in and out of the garage, trying to avoid or escape acid spillage and acid fumes, first with the H2SO4, and now with HNO3 (Phase 1 complete).

Update Thursday

...and the last of those comments had this appended as a postscript, though how many get to see it when a single individual then posts 6 comments in short order (more on the way?) remains to be seen. This blogger NEVER forgets those who abuse blog sites that have a fixed number of entries under Recent Comments, in this instance 10 only.

April 23, 2015 at 4:10 am
PS. After sleeping on that list of 10 points, all I would add for now is a gift wrapper in dubious good taste (thinking of the sensibilities that prevail generally on this site, with one or two notable exceptions).
There’s a bit of code in scientific research, summed up as “looking where the light is”. Charles Freeman is the historian with his “just a painting” thesis (dogma?) who is simply “looking where the light is”. PDL and his under-occupied ENEA pals with their employers’ laser beams are also looking where the light is, or what they imagine may have existed for a one-off instant in time, (and thus beyond the remit of science, JoeM).
My latest hypothesis explains why the TS is also a one-off, but of medieval provenance,and while difficult to fathom, is still definitely within the remit of science, provided one is prepared to think like a medieval, and not confine one’s search to where the light is.
My new starting point, a year or so ago, was to regard the TS as an attempt to replicate Joseph of Arimathea’s linen as it might have looked on arrival at the tomb, BEFORE being replaced by the real burial attire, i.e. Nicodemus’s “winding” sheets after washing and spices, oils etc. It was intended to be a bigger and better whole-body, front and back negative imprint (NOT painting) that would trump the Veil of Veronica, then the major draw for medieval pilgrims according to Neil McGregor, recently retired Director of the British Museum.
The task was to simulate a conjoint sweat and blood imprint, but to do it in a way that could/would stand up to the closest critical and sceptical scrutiny (barring the canny bishops of Troyes, watching the upstart ‘relic’ drawing funds away from their own cathedral upkeep ).
No, they did not scorch the body image with a heated template, not if the aim was to simulate an ancient sweat imprint. They consulted an alchemist, possibly one with a sympathetic religious disposition (Paul of Taranto, the Franciscan monk?). He in turn delivered state-of-the-art proto-chemical technology, in the form of nitric acid fumes, guaranteed to turn virtually any organic material into a yellow or brown stain on linen. Sure, it weakens the linen itself, but then the fibres on the TS ARE weaker than expected for something that is only 700 years old according to the radiocarbon dating (objections noted).
If as I suspect Paul of Taranto, or someone similar, was the brains behind the TS, then we have an explanation for why the TS image is exotic and such a well-kept secret (our alchemist/cleric may have thought that in harnessing his (al)chemical know how for the greater glory of God, he was saving souls that would otherwise have endured everlasting torment. In short, the ends justified the means. A similar hard-headed philosophy appears to prevail to this day (viz. current exposition in Turin).

Update: Friday 24th April:

David Goulet has asked how that hand imprint above responds in ImageJ.

Here's the result - a 5 minute job with no attempt to find the 'perfect' combination of settings.

Here's a Secondo Pia type light/dark reversal, one that restores the 'negative' image to a positive. (Used Edit Invert in ImageJ).

And here's the effect of some minor changes to the default settings in ImageJ's 3D rendering option. I've seen better. I've seen worse .

The Turin Shroud. was this the world's first and only tactile chemograph (think of it as a primitive 'photographic' negative, except for one tiny detail. Neither light not any other kind of elect6romagnetic radiation played any part in its production. It relied on the human touch (well, gentle massage actually).

What finally persuaded this blogger to abandon thermal scorching, and move to liquid (or semi-liquid) imprinting? It was that paper that Joe Accetta PhD presented at the St.Louis gathering, 2014, in which he propsoed that the TS image had been produced by woodblock imprinting. Up till that time I'd always been sceptical re the use of any kind of liquid imprinting medium, considering that would risk a reverse-side image. But I concocted my own equivalent of Joe's "oak gall" imprinting ink, in which the iron salts probably have a mordant action, as well as creating the ink by reaction with plant tannins. Here's an image produced, substituting tannin-rich pomegranate rind extract for oak galls, supplemented with iron (II)sulphate.

That 'wet' image was as good, if not better than anything produced by scorching. Yes. there was some reverse-side penetration, but might that not be minimized by suitable modification of technique, or simply by using thicker linen (and the TS linen IS thick, as Hugh Farey has observed).

Once liquid imprinting was permitted as an option, then a host of new experimental options were opened up. Thanks Joe Accetta. You weaned me of those thermal scorches (but they were useful in other ways, showing that ANY negative imprint can model certain key features of the TS, notably negative image and 3D-enhancibility). Models in science do not need to tick all boxes simultaneously. One can run different models in parallel, each earning its keep in one or other respect, while patiently waiting for the day when the super-model suggests itself, one  that combines the best features of its precursors, not only mine, but those of Garlaschelli and Accetta in particular. Hugh Farey and Adrie van der Hoeven added some useful and thought-provoking grist to the mill too, though whether they and the previous two would approve of the end-result is another matter.

Might tactile chemography prove to be the super-model? We shall see. These are early days, but I'm (how shall we say?) quietly confident.

Update Tuesday 28 April

Where next? Here are some thoughts posted earlier today to

  1. April 28, 2015 at 12:49 am
    As indicated earlier, I’m taking a break from experimentation, while taking stock of results so far (and the trickle of comments here and elsewhere).
    There are some new variants I shall be testing re the initial imprinting and subsequent development.
    Imprinting: is it better to do it as already described, with the imprinting medium placed first on the subject, before draping the linen over, OR is it better to do it Garlaschelli style (“frottage” as he calls it) where the linen is placed over first, and the medium then added last for moulding around contours?
    If I stick with my procedure, is it better to imprint LOTTO or LUWU configuration, those acronyms having been tested in my contact scorch model. (LOTTO = Linen On Top, Then Overlay; LUWU = Linen Underneath With Underlay) Each has its pros and cons where an inanimate template (statue, bas relief etc) is concerned, while for a real human being LOTTO is better obviously then LUWU.
    Then there’s the imprinting medium. The pilot study used a hot water dispersion of white wheat flour. I’m thinking of trying a cold water dispersion, so as to have intact endosperm cells.The latter have their starch granules and storage protein nicely enveloped in a primary cell wall sac whose composition will probably not be dissimilar from that of the superficial PCW of the linen fibre.

    Cross section of wheat grain. Note the internal cellular architecture of the endosperm, and the 'graininess' of the latter due to starch granules and storage protein.

    SEM photomicrograph of internal structure of the wheat grain, Note the large endosperm cell, note its thin (primary) cell wall, note the much smaller starch granules within the endosperm cells.

    On the general principle that like is attracted to like in organic chemistry (polar/polar; apolar/apolar) , there might be something to be said for bonding a compatible microparticulate substance to the linen first as a possibly more receptive carpet for image capture.
    Finally, I shall try substituting a purely thermal treatment for nitric acid vapour.(essentially Garlaschelli technology). That too might produce a TS like coloration and image, either by oxidation of carbohydrates OR via Maillard reactions between sugars and proteins (yup, we’ve been there before in the scorch model, but here the chemistry is being tested in the new two step imprinting/developing model for which I have high hopes.

    Update Sunday May 3

    This comment has just appeared on the shroudstory site.(I've omitted allexcept the last paragraph):

    daveb of wellington nz
    May 2, 2015 at 7:34 pm

    Colin has now been attempting to reproduce the properties of the image for some three years, with indifferent success only, although I applaud his perseverance. Might we suppose that a less chemistry-informed artisan would have struck it lucky any sooner? As one early commentator observed, Colin is more likely to end up proving the resurrection from all his efforts.

    Don't you just love the man's pomposity?

    Here's my reply (Yes, I'm sitting on something just 12 hours old that could give the new model a real boost):

    May 3, 2015 at 12:22 am
    Colin is continuing to do open-ended experimentation. He has just stumbled on an entirely unpredicted effect with his new cheiropoietic hand/flour/water model (Stage 1 imprinting), one that is arguably replete with possible implications re image fuzziness. It’s to do with instant adhesion, dare one suggest ‘medieval superglue’. It’s to do with instant fleecing-up of linen. Details later.


    Ooops. I'm doing myself down in that comment, since I did in fact predict the effect just a week ago in these words from above:

    "On the general principle that like is attracted to like in organic chemistry (polar/polar; apolar/apolar) , there might be something to be said for bonding a compatible microparticulate substance to the linen first as a possibly more receptive carpet for image capture."

    Have been on holiday this last week. Mind's gone a blank.

    The key word? The new lead?  Answer: adhesion. That's instant adhesion.